I would think Harris Chassis would be able to offer that kind of help. As a matter of fact, any good builder of a 3-link car should have your explanation
Steve Smith used to have several books out about the building, setup and driving of race cars, both dirt and pavement. The books may be available on Amazon or EBay. Also try the web for “ron miller race cars” or “proven chassis”, click on the “by ron miller race cars”. Then click on “technical help” on that web site. It will give a lengthy and detailed description of a dirt late model starting set up. You can start with these settings and fine tune them for your track or individual car.
Did you build the car yourself? Is it a Teo Pro Car, Troyer or Bicknell? If they are unwilling to help, an independent racer such as Steve Paine or Lee Osborne (Pen Yann NY) could lend a hand. As you know Lee worked with the late **** Tobias and Dick’s sons designing and building three link modifies. I’d be a hindrance, I’ve worked on three link asphalt modifies and super stock dirt late models (Ed Carley cars).